Parachute inlet control system and method

ABSTRACT

A parachute inlet control system is configured to provide an improved inflation profile for solo and/or clustered parachutes. An inlet parachute is coupled to a main parachute via a plurality of lacing loops and/or reefing rings. The lacing loops may be passed through the reefing rings and/or may be routed around one or more of the main parachute suspension lines. The inlet parachute is located in the inlet area of the main parachute, and causes the inlet of the main parachute to rapidly form a desirable shape. The inlet parachute and lacing loops function as a reefing means, and prevent full inflation of the main parachute until a reefing cutter has functioned. In this manner, parachute failures, such as those due to leading and/or lagging parachutes in a parachute cluster, may be reduced or eliminated.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Ser. No. 12/535,099 filed onAug. 4, 2009, now U.S. Pat. No. 8,096,509 entitled “PARACHUTE INLETCONTROL SYSTEM AND METHOD”. U.S. Ser. No. 12/535,099 claims priority toand is a non-provisional of U.S. Provisional No. 61/086,959 filed onAug. 7, 2008 and entitled “PARACHUTE INLET CONTROL SYSTEM.” The entirecontents of each of the foregoing applications are hereby incorporatedby reference.

TECHNICAL FIELD

The present disclosure relates to parachutes, and more particularly tolarge-scale parachutes deployed solo or in clusters to support heavyand/or bulky payloads.

BACKGROUND

Large cargo parachutes are typically constructed to have a flat disccanopy of approximately 100 feet in diameter, although some are smallerand a few are larger. A 100 foot diameter cargo parachute may typicallybe used for recovering an aerial delivered payload having a weight rangefrom approximately 2,500 pounds to 5,000 pounds. Payloads of less thanapproximately 2,500 pounds would most often use a cargo parachute havinga smaller diameter. If the payload weight is between approximately 5,000pounds and 10,000 pounds, another 100 foot diameter parachute istypically added beside the original parachute. The resulting arrangementis known as a 2-chute cluster. Similarly, payload weights of betweenapproximately 10,000 pounds and 15,000 pounds typically use three 100foot diameter parachutes as a 3-chute cluster. Further, eachapproximately 5,000 pound payload weight increase typically requires anadditional 100 foot diameter parachute.

The initial inflation phase of parachute deployment is typically quitedynamic and somewhat chaotic. Therefore, a typical 2-chute parachutecluster will have more inflation difficulties than will a singleparachute, and each additional parachute added to a cluster furtherincreases the potential for a parachute to fail. Because of theseissues, a parachute cluster having more than eight 100 foot diameterparachutes is extremely unusual. Primarily, the problems begin with whatare referred to as “leading” and/or “lagging” parachutes.

If one of the parachutes in a cluster is slow to initially ingest air (a“lagging” parachute), other inflating parachutes may block its air inletarea and it may not inflate at all. If one or more parachutes in acluster fail to inflate, the rate of descent for the payload will behigher than desired. The payload may be damaged or destroyed at landing.

Conversely, if one parachute in a cluster of parachutes ingests air inadvance of the others within a cluster (a “leading” parachute), it maybecome overloaded and rupture. If another parachute then leads, it toomay overload and rupture. A chain reaction may follow until allparachutes in the cluster have catastrophically failed.

In an attempt to minimize these and other parachute inflation problems,large cargo parachutes are typically equipped with a “reefing” system toprovide some control to the initial parachute inflation stage. A typicalreefing system consists of a series of reefing rings attachedcircumferentially around the periphery of the parachute canopy, areefing line, and a reefing line cutter. The reefing line is passedthrough the reefing rings, and prevents the parachute canopy fromopening fully. Therefore, this conventional reefing system is somewhatanalogous to a set of trouser belt loops, having a belt sequentiallythreaded through them, with the belt tightly cinched until the reefingline cutter severs it. Once the reefing line is severed, the parachuteis no longer restrained by the reefing line and the parachute ispermitted to fully inflate. Even with a reefing system, however, initialinflation of individual parachutes in a parachute cluster is somewhatrandom, and many parachute failures still occur.

Additionally, typical aerial delivery operations occur at relatively lowaltitudes. Therefore, reefing line cutters having short delays, such as2.5 seconds, are typically used. But, within a particular cluster ofparachutes, these relatively short reefing times often do not provide asufficient time interval for the reefing systems to provide optimalcontrol of the individual parachute canopy air inlets before the reefingcutters sever their reefing lines. Delaying the disreefing event, forexample by incorporating longer delay reefing cutters, may allow moretime for the individual reefing systems to provide better initialparachute inflation control, but may also allow the payload to reach theground surface before full inflation of the parachutes can occur.Therefore, while longer reefing times may improve the success rate ofsome aerial delivery systems, the altitude from which the aerialdelivery operation occurs must be increased to allow more reefing time.This is generally an undesirable option, because most aerial deliveryoperations are conducted as part of larger military operations. Thus,factors other than parachute reefing times play a significant role inselecting the preferred aerial delivery altitude.

Therefore, it remains desirable to achieve a greater degree of controlover the inflation process for solo and/or clustered parachutes, forexample parachutes utilized for aerial delivery operations.

SUMMARY

A parachute inlet control system and methods for use are disclosed. Inan exemplary embodiment, a parachute inlet control system forfacilitating controlled inflation of a main parachute comprises aparachute component comprising an inlet parachute, a reefing componentcomprising a plurality of lacing loops configured to couple the inletparachute to a main parachute, and a release component comprising areefing cutter configured to separate the inlet parachute from the mainparachute.

In another exemplary embodiment, a method for inflating a parachutecomprises providing an inlet parachute, and coupling the inlet parachuteto a main parachute. The inlet parachute is configured to inflate withinthe inlet area of the main parachute.

In another exemplary embodiment, a method for controlling operation of aparachute cluster comprises coupling at least two main parachutes toform a parachute cluster, coupling a parachute inlet control system toeach main parachute in the parachute cluster, and deploying theparachute cluster to support a payload. Each parachute inlet controlsystem is activated to cause the inlet area of each main parachute toassume a desired shape. A reefing cutter associated with each parachuteinlet control system is activated to allow each main parachute in theparachute cluster to further inflate.

In another exemplary embodiment, a tangible computer-readable medium hasstored thereon, computer-executable instructions that, if executed by asystem, cause the system to perform a method. The method comprisesactivating a reefing cutter to cause an inlet parachute to separate fromthe skirt of a main parachute. The inlet parachute is inflated in theinlet area of the main parachute, and the inlet parachute is coupled tothe main parachute via a plurality of lacing loops threaded throughreefing rings located on the skirt of the main parachute.

The contents of this summary section are provided only as a simplifiedintroduction to the disclosure, and are not intended to be used to limitthe scope of the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

With reference to the following description, appended claims, andaccompanying drawings:

FIG. 1A illustrates a bottom view of a flat circular parachute;

FIG. 1B illustrates a hemispherical parachute;

FIG. 1C illustrates various parachute air inlet shapes;

FIG. 1D illustrates a side view of a main parachute with and without acenter line;

FIG. 1E illustrates a bottom view of a reefed parachute;

FIG. 1F illustrates a block diagram of a parachute inlet control systemin accordance with an exemplary embodiment;

FIG. 2A illustrates a side view of a main parachute coupled to an inletparachute in accordance with an exemplary embodiment;

FIG. 2B illustrates a bottom view of an inlet parachute installed in theair inlet area of a main parachute having a single lacing loop for eachmain parachute reefing ring in accordance with an exemplary embodiment;

FIG. 2C illustrates a bottom view of an inlet parachute installed in theinlet area of a main parachute having a single lacing loop for each twomain parachute reefing rings in accordance with an exemplary embodiment;

FIG. 3 illustrates a side view of an inflated center-lined parachute,and an isometric view of a parachute vent ring in accordance with anexemplary embodiment;

FIG. 4A illustrates a main parachute in a reefed and disreefed conditionin accordance with an exemplary embodiment;

FIG. 4B illustrates a main parachute having a pulled down ventconfiguration in a reefed and disreefed condition in accordance with anexemplary embodiment;

FIG. 4C illustrates a main parachute having a pulled down ventconfiguration, and an inflated inlet parachute in the main vent thereofin accordance with an exemplary embodiment;

FIG. 4D illustrates a main parachute having a pulled down ventconfiguration, and an inlet parachute coupled thereto after a parachuteinlet control system has ceased to function as a reefing means inaccordance with an exemplary embodiment;

FIG. 4E illustrates vent lines of a main parachute and vent lines of aninlet parachute in accordance with an exemplary embodiment;

FIG. 4F illustrates a main parachute and an inlet parachute coupled to apull-down strap in accordance with an exemplary embodiment; and

FIG. 5 illustrates portions of a parachute inlet control systemconfigured to facilitate retaining a reefing cutter near the skirt of amain parachute after operation of the reefing cutter in accordance withan exemplary embodiment.

DETAILED DESCRIPTION

The following description is of various exemplary embodiments only, andis not intended to limit the scope, applicability or configuration ofthe present disclosure in any way. Rather, the following description isintended to provide a convenient illustration for implementing variousembodiments including the best mode. As will become apparent, variouschanges may be made in the function and arrangement of the elementsdescribed in these embodiments without departing from the scope of theappended claims.

For the sake of brevity, conventional techniques for parachuteconstruction, grouping, deployment, recovery, reefing, disreefing,and/or the like may not be described in detail herein. Furthermore, theconnecting lines shown in various figures contained herein are intendedto represent exemplary functional relationships and/or physicalcouplings between various elements. It should be noted that manyalternative or additional functional relationships or physicalconnections may be present in a practical parachute inlet controlsystem.

Primarily because of construction costs, a common generally circularparachute type is constructed as a polygon, but is known as a flatcircular parachute, and is typically constructed from tapered gores 100Aforming a flat-disc parachute canopy, as depicted by FIG. 1A. The flatcircular parachute 100 canopy has an inflated diameter that is abouttwo-thirds (⅔) of its constructed diameter. However, during initialinflation, flat circular parachute 100 can momentarily “over-inflate”and nearly reach its flat-disc constructed diameter if the parachute isnot reefed. This is undesirable, because very high forces are developedduring such an over-inflation occurrence. The parachute in question mayfail under the high forces. Additionally, the payload may be damaged ordisturbed.

Turning to FIG. 1B, a generally hemispherical parachute canopy, such asthe canopy of hemispherical parachute 110, may be constructed with knowngore-shaping components, for example via use of curved gores 110A.Hemispherical parachute 110 typically has a constructed diameter whichis nearly equal to its inflated diameter. While a hemisphericalparachute is less prone to over-inflation than a flat circularparachute, a hemispherical parachute may still overinflate, and may alsostill become a leading and/or a lagging parachute when deployed in aparachute cluster.

With reference now to FIG. 1C, a substantially circular parachute airinlet 130 is presented. Suspension line attachment points A-F are shownaround the periphery of inlet 130. Due to the somewhat chaoticconditions associated with the initial deployment of a parachute, beforethe parachute canopy skirt has become taut, a portion of the peripheryof an air inlet may partially or fully traverse a desired circular airinlet area, as illustrated by partially collapsed air inlet 140. If aportion of the periphery of partially collapsed air inlet 140 passesbetween suspension lines on another portion of the periphery ofpartially collapsed air inlet 140 (for example, if suspension lineattachment point C and/or D on partially collapsed air inlet 140 passesbetween suspension line attachment points A and B, as illustrated by thedirectional arrow in FIG. 1C), a portion of the main parachute canopymay then inflate outside what should be the parachute canopy periphery.This typically results in a parachute malfunction known as a “Mae West.”

Turning now to FIG. 1D, a parachute, such as main parachute 160, mayhave suspension lines attached only at the edges of the parachutecanopy. However, a parachute, such as main parachute 170, may have astrap or line, such as center line 172, extending from the parachutecanopy apex to a point below the parachute canopy, for example asuspension line convergence point. Typically, the length of center line172 is only somewhat longer than the peripheral suspension lines, sothat center line 172 will pull the inflated canopy apex down toward thegeneral elevation of the canopy skirt. This configuration causes thecanopy to form a shape somewhat resembling a “split bagel” or partialtorus. When the parachute apex is pulled downward, the parachute canopymay bulge outward more than it otherwise would, and thus the projectedarea of the parachute is increased. Additionally, a center-linedparachute canopy shape may be less aerodynamically streamlined, with acorresponding increase in drag.

Additionally, to help a parachute inflate in a controlled manner, areefing system may be used. A reefing system restricts the inlet size ofa parachute, and thus prevents the parachute from fully inflating untilthe reefing system is released. FIG. 1E depicts a bottom view of atypical circular main parachute having a typical reefing line, typicalreefing rings, and typical reefing line cutter. One goal of aconventional reefing system is prevention of a leading parachute withina parachute cluster. However, conventional reefing systems areinefficient at this task if they do not maintain control of theparachute canopy inlet long enough for each canopy in a parachutecluster to form a symmetrical, fully reefed shape. Moreover,conventional reefing systems have no means to encourage a laggingparachute to catch up to any other parachute in the parachute cluster.Accordingly, a parachute inlet control system may be provided in orderto control, guide, and/or otherwise influence inflation, reefing, and/ordisreefing of one or more main parachutes.

A parachute inlet control system may be any system configured tofacilitate controlled inflation, reefing, and/or disreefing of a mainparachute. In accordance with an exemplary embodiment, and withreference to FIG. 1F, a parachute inlet control system 101 generallycomprises a parachute component 101A, a reefing component 101B, and arelease component 101C. Parachute component 101A is configured toprovide a force to inflate, shape, and/or otherwise facilitate, control,and/or guide opening of the intake vent of a main parachute. Reefingcomponent 101B is coupled to parachute component 101A, and is configuredto restrict the opening of the intake vent of a main parachute beyond adesired point (for example, beyond a desired intake vent diameter, sizeand/or area). Release component 101C is coupled to parachute component101A and/or reefing component 101B, and is configured to sever, cut,and/or otherwise facilitate at least partial separation of parachuteinlet control system 101 from a main parachute.

Through use of a parachute inlet control system, such as parachute inletcontrol system 101 in FIG. 1F, various shortcomings of conventionalparachutes and parachute clusters may be overcome. Leading and laggingparachutes may be reduced and/or eliminated. Over-inflation of circularparachutes may be prevented. “Mae West” malfunctions and other parachuteinlet anomalies may be reduced and/or prevented. Additionally, parachuteinlet control system 101 may be configured to enable these benefits formain parachutes lacking a center line, as well as for main parachuteshaving a center line.

With reference now to FIGS. 2A-2C, and in accordance with an exemplaryembodiment, a parachute inlet control system 101 (for example, parachuteinlet control system 200) comprises inlet parachute 202, a plurality oflacing loops 204 each having an end loop 206, and at least one reefingcutter 212. Inlet parachute 202 may also comprise one or more vent holes214. A plurality of reefing rings 210 are provided on a main parachute208, as depicted in FIG. 2A. Parachute inlet control system 200 iscoupled to main parachute 208 at reefing rings 210. Alternatively,parachute inlet control system 200 may be coupled to main parachute 208at locations other than reefing rings 210, for example at suspensionlines of main parachute 208.

Inlet parachute 202 may comprise any component, structure, materials,and/or mechanisms configured to apply a force to an inlet vent of a mainparachute. In accordance with an exemplary embodiment, inlet parachute202 comprises a hemispherical parachute. In another exemplaryembodiment, inlet parachute 202 comprises a semispherical cruciformparachute, for example a parachute disclosed in U.S. Pat. No. 7,261,258to Fox. Moreover, inlet parachute 202 may comprise any suitableparachute configured to inflate in the inlet area of main parachute 208.

In an exemplary embodiment, inlet parachute 202 comprises nylon fabric.Additionally, inlet parachute 202 may comprise polyethyleneterephthalate (e.g., Dacron®), ultra-high molecular weight polyethelyne(e.g., Spectra®), poly paraphenylene terephthalamide (e.g., Kevlar®),and/or other high-modulus aramid fibers, and the like. For example,inlet parachute 202 may comprise nylon gores coupled to Kevlar® fabricreinforcing portions in various locations. Moreover, inlet parachute 202may comprise any suitable material or combination of materialsconfigured to inflate in response to movement through an air stream.

Further, inlet parachute 202 may also comprise one or more vent holes214. In an exemplary embodiment, a vent hole 214 is located in thecenter of inlet parachute 202. Moreover, one or more vent holes 214 maybe located at any suitable location on inlet parachute 202 in order tofacilitate operation of inlet parachute 202, as desired.

In an exemplary embodiment, inlet parachute 202 is coupled to reefingrings 210 via lacing loops 204. Moreover, inlet parachute 202 may becoupled to main parachute 208 via any suitable mechanism and/or at anysuitable location configured to cause the inlet area of main parachute208 to expand to and/or assume a desired shape.

In accordance with an exemplary embodiment, inlet parachute 202 iscoupled to main parachute 208 via a tether line. The tether lineprevents inlet parachute 202 from drifting away from main parachute 208after reefing cutter 212 has functioned. In this manner, inlet parachute202 may be more easily recovered and/or reused. In various exemplaryembodiments, a center line, such as center line 304 depicted in FIG. 3,may tether inlet parachute 202 to main parachute 208.

In accordance with various exemplary embodiments, inlet parachute 202may be customized for use with a particular main parachute and/orpayload. For example, inlet parachute 202's size, shape, configuration,material, vent size, vent location, and/or the like may be configuredbased on a desired inflation time for main parachute 208. Moreover,inlet parachute 202 may be configured based on any suitable criteria asdetermined by a user, for example payload size, payload weight,deployment velocity, inlet size of main parachute 208, and/or the like.

Lacing loops 204 may comprise any suitable material, fabric, rope, cord,and/or the like, configured to releasably couple inlet parachute 202 andmain parachute 208. In accordance with an exemplary embodiment, lacingloops 204 comprise high-strength cord coupled to inlet parachute 202 andreefing rings 210. In various exemplary embodiments, lacing loops 204comprise Spectra® fiber. In other exemplary embodiments, lacing loops204 comprise Kevlar® fiber. In various exemplary embodiments, lacingloops 204 are configured to have a length of between approximately 10%and 50% of the diameter of inlet parachute 202. In another exemplaryembodiment, lacing loops 204 are configured to have a length ofapproximately 20% of the diameter of inlet parachute 202. Moreover,lacing loops 204 may comprise any suitable configuration, shape, length,thickness, mass, density, and/or material configured to couple parachute202 to main parachute 208 and/or reefing rings 210.

In accordance with an exemplary embodiment, each lacing loop 204comprises an end loop 206, as depicted in FIG. 2B. When parachute inletcontrol system 200 is coupled to main parachute 208, each lacing loop204 is passed through end loop 206 of an adjoining lacing loop 204. Inthis manner, inlet parachute 202 may be secured to main parachute 208and/or reefing rings 210 in a stable configuration. Additionally, inthis manner inlet parachute 202 may be rapidly separated from mainparachute 208 and/or reefing rings 210 responsive to function of areefing cutter, for example reefing cutter 212 as depicted in FIG. 2B.

With reference now to FIGS. 2A and 2B, and in an exemplary embodiment,lacing loops 204 are sequentially threaded through reefing rings 210 ofmain parachute 208. Additionally, each lacing loop 204 is sequentiallythreaded through end loop 206 of an adjoining lacing loop 204. This maybe accomplished by selecting a location on the edge of inlet parachute202 as a point of origin. From this point of origin, lacing loops 204and reefing rings 210 are threaded in a sequential manner clockwise fromthe point of origin. Similarly, lacing loops 204 and reefing rings 210are threaded in a sequential manner counterclockwise from the point oforigin. Thus, two lacing loops 204 are coupled to the edge of inletparachute 202 at the point of origin.

In this manner, lacing loops 204 and reefing rings 210 are threadedtogether around the inlet perimeter of main parachute 208. In anexemplary embodiment, the counterclockwise threaded portion and theclockwise threaded portion are of equal length, and thus meet up at alocation on the edge of inlet parachute 202 directly across from thepoint of origin. In various other exemplary embodiments, the clockwisethreaded portion and the counterclockwise threaded portion have unequallengths. When the two threaded portions meet, the final two lacing loops204 are coupled to each other and to the periphery of inlet parachute202 with a cut loop 216. Cut loop 216 is configured to be severed viaoperation of reefing cutter 212.

The foregoing illustration illustrates use of a single point of origin,a single cut loop, and a single reefing cutter. However, multiple pointsof origin, clockwise and/or counterclockwise threaded portions, cutloops, and reefing cutters may also be used. In these exemplaryembodiments, one or more disreefing events may occur if desired.

Reefing rings 210 may comprise any suitable structure, material, shape,size, and/or configuration to facilitate coupling a main parachute 208to an inlet parachute 202. Continuing to reference FIG. 2B, and inaccordance with an exemplary embodiment, a plurality of reefing rings210 are coupled to main parachute 208 around the periphery of the mainparachute 208 air inlet. Reefing rings 210 may comprise metal (e.g.,aluminum, steel, titanium, magnesium, and the like, and/or alloys andcombinations of the same), plastic, composite, textile, or any othersuitable material configured to couple with lacing loops 204. Reefingrings 210 may be located in any suitable location on main parachute 208.For example, a reefing ring 210 may be located on the canopy skirt ofmain parachute 208 at the junction of each radial seam, and/or betweenadjacent gores and a suspension line. In an exemplary embodiment, onereefing ring 210 is provided for each gore of main parachute 208. Inanother exemplary embodiment, two reefing rings 210 are provided foreach gore of main parachute 208. Moreover, any suitable number ofreefing rings 210 may be coupled to main parachute 208 in order tofacilitate coupling of main parachute 208 to inlet parachute 202 and/orto control the inflation of main parachute 208.

In various exemplary embodiments, lacing loops 204 are threaded throughreefing rings 210. With continued reference to FIG. 2B, and in anexemplary embodiment, one lacing loop 204 is threaded through onereefing ring 210. With reference now to FIG. 2C, and in anotherexemplary embodiment, one lacing loop 204 is threaded through tworeefing rings 210. Moreover, one lacing loop 204 may be passed throughany suitable number of reefing rings 210 in order to achieve a desiredinflation profile for main parachute 208. Additionally, multiple lacingloops 204 may be passed through a single reefing ring 210.

Main parachute 208 may comprise any suitable material or combination ofmaterial in any suitable configuration to slow the descent of a desiredpayload. In accordance with an exemplary embodiment, main parachute 208is configured to slow the descent of a payload through the atmosphere.In various exemplary embodiments, main parachute 208 may be a flatcircular parachute, a hemispherical parachute, a cruciform parachute,and the like. Main parachute 208 may be deployed alone, or may be partof a parachute cluster. Moreover, main parachute 208 may be configuredwith any suitable components to enable use with parachute inlet controlsystem 200, as desired. Main parachute 208 is further configured toinflate responsive to operation of one or more reefing cutters 212.

Reefing cutter 212 may comprise any suitable mechanism configured tofacilitate at least partial separation of inlet parachute 202 and mainparachute 208, for example by severing cut loop 216. In accordance withan exemplary embodiment, reefing cutter 212 comprises a pyrotechniccharge configured to force a blade through a cord. In accordance withvarious exemplary embodiments, reefing cutter 212 is configured to severcut loop 216 between approximately 1.5 seconds and 5 seconds after mainparachute 208 is deployed. In another exemplary embodiment, reefingcutter 212 is configured to sever cut loop 216 2.5 seconds after mainparachute 208 is deployed. Moreover, reefing cutter 212 may beconfigured to sever cut loop 216 at any suitable time configured tofacilitate a desired inflation profile for main parachute 208, and theexamples provided herein are for way of illustration and not oflimitation.

Additionally, reefing cutter 212 may be configured for remote operation.For example, reefing cutter 212 may be configured with wirelesscommunication components allowing a user to send an operative command,for example an activation command, to reefing cutter 212 and/or othercomponents of parachute inlet control system 200. In this manner, a usermay monitor the inflation of a main parachute 208, and may triggeroperation of reefing cutter 212 once a desired inflation profile formain parachute 208 has been achieved. Additionally, a user may monitorthe inflation of multiple main parachutes 208 configured as a parachutecluster, and may trigger operation of one or more reefing cutters 212 ata desired time, for example once all main parachutes 208 in theparachute cluster have achieved a desired inflation profile. Reefingcutter 212 may also be configured to activate after a predetermined timeperiod (for example, 10 seconds) if an operative command has not beenreceived. Reefing cutter 212 may further be configured to be activatedresponsive to any suitable condition, for example altitude of a payload,velocity of a payload, atmospheric pressure, temperature, and/or thelike, as desired.

Continuing to reference FIGS. 2A-2C, and in accordance with variousexemplary embodiments, parachute canopies generally inflate by allowingair to enter the bottom of the parachute canopy. The air is then trappedinside the canopy, forming a bubble at the parachute top that growslarger and larger, inflating and pressurizing the parachute canopy fromtop to bottom. Thus, at least partially blocking the air inlet into thecanopy of a parachute, for example main parachute 208, by coupling aninlet parachute 202 in this area may seem to be the exact opposite ofwhat is needed to encourage a speedy reefed inflation of main parachute208. However, small parachutes, such as inlet parachute 202, inflatemuch more rapidly than large parachutes. Therefore, a small parachutestrategically positioned inside the air inlet of main parachute 208 canrapidly inflate and quickly force the air inlet of main parachute 208into a desirable shape. This is especially true if inlet parachute 202is constructed of low permeability fabric. Moreover, because lacingloops 204 on inlet parachute 202 allow the inlet of main parachute 208to spread to a somewhat larger diameter than that of inlet parachute202, high velocity air flows around inlet parachute 202 and fills mainparachute 208.

Additionally, the canopy of inlet parachute 202 can be equipped with oneor more vent holes 214 configured to flow air therethrough and into thecanopy of main parachute 208. Thus, inlet parachute 202 does not blockair flow into main parachute 208, because inlet parachute 202 rapidlybecomes centered in the inlet of main parachute 208, and thus at leastpartially controls, guides, and/or directs air flow into main parachute208. Because the perpendicular component of the air flow around inletparachute 202 rapidly forces the skirt of main parachute 208 into adesirable shape, main parachute 208 becomes configured to ingest airmore uniformly, and thus more rapidly, with inlet parachute 202 in placethan without inlet parachute 202 in place. Further, such an approach isvery effective in preventing lagging main parachutes in a parachutecluster. In a parachute cluster having main parachutes equipped withparachute inlet control system 200, such as that depicted in FIG. 2A,each main parachute canopy air inlet rapidly forms a desirable shapealmost simultaneously.

Further, because lacing loops 204 of inlet parachute 202 are secured tomain parachute 208 and/or reefing rings 210 until reefing cutter 212severs cut loop 216, parachute inlet control system 200 also serves thefunction of a conventional reefing line, and thus prevents mainparachute 208 from initially over-inflating or otherwise spreadingexcessively and becoming a leading parachute. Therefore, parachute inletcontrol system 200 facilitates greater control of the inflation and/oroperation of main parachute 208. Further, the inflation, reefing, anddisreefing events of one or more main parachutes 208 within a parachutecluster may thus achieve a degree of synchronization beyond that whichis possible with typical clustered parachute systems.

As noted previously, even a single parachute can suffer from lack ofcanopy air inlet control during the initial inflation phase, which canlead to a parachute malfunction, parachute damage, and/or loss of ordamage to a payload. Accordingly, parachute inlet control system 200 maybe coupled to a single main parachute to provide improved inflation anddisreefing control.

Additionally, parachute inlet control system 200 may be configured tofacilitate multiple reefing stages for a parachute, for example mainparachute 208. In accordance with various exemplary embodiments,parachute inlet control system 200 may function as the first reefingstage of main parachute 208. Additional reefing systems may be providedon main parachute 208 to obtain a multi-stage reefed inflation. Forexample, main parachute 208 may also be coupled to a second reefing lineand to a third reefing line that is longer than the second reefing line.Parachute inlet control system 200 may then be coupled to main parachute208 in a manner configured to function as a first reefing line shorterthan the second reefing line. In this way, main parachute 208 mayachieve a multi-stage reefed inflation responsive to operation ofparachute inlet control system 200 and one or more additional reefinglines, allowing main parachute 208 to achieve a fully inflatedconfiguration in stages. Multi-stage inflation may be highly desirable,for example when main parachute 208 is deployed when the associatedpayload is traveling at a high velocity.

Because many main parachutes are configured with a center line, withreference now to FIGS. 1D and 3, and in accordance with variousexemplary embodiments, parachute inlet control system 200 may beutilized in conjunction with a main parachute having a center line, forexample main parachute 300 in FIG. 3. Center line 304 of main parachute300 is passed through a vent centrally located on inlet parachute 302.Because friction may damage center line 304 and/or inlet parachute 302,the edges of the vent through which center line 304 is passed have afriction reducing means installed. For example, the edges of the ventmay be coated with a friction reducing material, such as Teflon®material, Spectra® fabric, and/or the like. Alternatively, a vent ring306, for example a plastic or metallic ring, may form the edge of thevent. Vent ring 306 is then coupled to the main body of inlet parachute302 via any suitable technique and/or means, as desired.

When a reefing cutter is activated, inlet parachute 302 separates fromthe reefing rings coupling inlet parachute 302 to main parachute 300.Inlet parachute 302 then rises up along center line 304 toward the apexof main parachute 300. In this manner, inlet parachute 302 does notinterfere with the full inflation of main parachute 300.

However, in general the coupling of one or more reefing rings to theskirt of a main parachute is a weak link in the resulting parachuteassembly. Stated another way, responsive to a sufficient force, one ormore reefing rings may be ripped away from the main parachute.Additionally, a main parachute may be configured without a reefing ringat one or more locations. Accordingly, with reference again to FIG. 2A,parachute inlet control system 200 may be configured to reduce the forceon one or more reefing rings associated with a main parachute and/or tointerface with a main parachute having one or more locations without areefing ring. In certain exemplary embodiments, parachute inlet controlsystem 200 is configured to interface with a main parachute having noreefing rings. Moreover, in accordance with an exemplary embodiment,parachute inlet control system 200 is configured with one or more lacingloops 204 and/or inlet vent lines configured to interface with a mainparachute suspension line, a main vent line, and/or other portions of amain parachute.

For example, certain main parachutes, such as the U.S. governmentstandard G-11 cargo parachute (a main parachute having a 120 gore, 100foot diameter construction) have one or more locations on the intakeskirt where a reefing ring is not present. For example, the G-11 cargoparachute typically utilizes four reefing cutters arranged at 90 degreeintervals around the intake skirt; accordingly, the intake skirt of aG-11 parachute is configured with four corresponding locations lacking areefing ring. In various exemplary embodiments, however, parachute inletcontrol system 200 is configured with a reefing cutter 212 at only onelocation. Thus, coupling this particular parachute inlet control system200 to this particular G-11 cargo parachute as described above may leavethe skirt of the G-11 parachute unreefed at the remaining three legacyreefing cutter locations (moreover, as can be appreciated, many otherreefing cutter/reefing ring location mismatches may occur between aparticular main parachute and a particular parachute inlet controlsystem 200, and may be suitably addressed as per the below).

In order to avoid this undesirable condition, one or more lacing loops204 associated with an inlet parachute 202 may be threaded between,encircled around, and/or otherwise coupled to or interfaced with a mainparachute suspension line, for example a main parachute suspension lineproximate to a location on the main parachute skirt lacking a reefingring. In this manner, a suitable amount of control over the inflation ofthe main parachute is facilitated, and parachute inlet control system200 can impart a force to the main parachute at these locations.Additionally, because parachute inlet control system 200 is now coupledto the main parachute in additional locations, stress on the remainingmain parachute reefing ring(s) (for example, reefing rings adjacent tothe area on the main parachute skirt lacking reefing rings) is reduced,further reducing the chance of parachute failure. Moreover, one or morelacing loops 204 may at least partially encircle, surround, threadthrough, weave between, and/or otherwise interface with and/or couple toone or more main parachute suspension lines, as desired.

Additionally, a main parachute may be configured without reefing rings,and parachute inlet control system 200 may thus be configured to becoupled to a main parachute lacking reefing rings in order to at leastpartially control inflation, reefing, and/or disreefing of the mainparachute. In an exemplary embodiment, parachute inlet control system200 is coupled to a main parachute by encircling one or more suspensionlines of the main parachute with a lacing loop 204. In this manner,controlled inflation of the main parachute may be facilitated, eventhough the main parachute lacks reefing rings. Thus, the skirt of a mainparachute may suitably be controlled, configured, managed, and/orotherwise guided before, during, and/or after deployment by use ofparachute inlet control system 200, as desired.

As discussed previously, with reference now to FIGS. 4A and 4B, a mainparachute 208 (for example, main parachute 408) may utilize a pulleddown vent configuration (as shown in FIG. 4B, and as further illustratedin FIG. 1D by main parachute 170 having a pulled down vent configurationresponsive to the presence of center line 172) because thisconfiguration allows main parachute 408 to expand and produce a largerprojected diameter than a similar main parachute 408 configured with acanopy lacking a pulled down vent. In accordance with an exemplaryembodiment, parachute inlet control system 200 may be configured for usewith a main parachute 408 having a center line, for example pull-downstrap 420. When parachute inlet control system 200 is deployed inconnection with main parachute 408, main parachute 408 is allowed topartially inflate as illustrated in FIG. 4C. In connection with adisreefing event for main parachute 408, inlet parachute 402 separatesfrom the skirt of main parachute 408 and is retained around the pulleddown vent area of main parachute 408, as illustrated in FIG. 4D.

Moreover, with reference to FIG. 4E, cordage or webbing members, such asmain vent lines 440 (often constructed similarly to a suspension line)typically extend across the central vent of main parachute 408 in orderto transfer forces and/or loads, for example from one structural memberof main parachute 408 to another structural member located on theopposite side of main parachute 408. Parachute inlet control system 200may also suitably be configured with an inlet parachute 402 havingcontinuous inlet vent lines 450; however, parachute inlet system 200 maypreferably be configured with an inlet parachute 402 having inlet ventlines 450 configured with terminal end loops 452.

In an exemplary embodiment, inlet parachute 402 is installed around thepulled down vent of main parachute 408. Inlet parachute 402 is coupledto pull-down strap 420 via inlet vent lines 450. For example, the endloop 452 of each inlet vent line 450 may be coupled to a metal ring 456via one or more tie cords 454. Metal ring 456 is coupled to pull-downstrap 420 via stitching or other suitable method. Main vent lines 440are also coupled to metal ring 456. Moreover, pull-down strap 420 may becoupled to main vent lines 440 and/or inlet vent lines 450 via a metalring, a tie cord, stitching, and/or any other suitable mechanism ormethod.

Moreover, with reference again to FIGS. 2A and 2B, in certain exemplaryembodiments, lacing loops 204 of parachute inlet control system 200 aresequentially laced around the periphery of main parachute 208 andterminate at a single point at the skirt of inlet parachute 202. Inthese configurations, it may not be desirable to allow an expendedreefing cutter 212 to remain on the skirt of inlet parachute 202 afteroperation of reefing cutter 212. For example, when inlet parachute 202is released from the periphery of main parachute 208, inlet parachute202 may rapidly rise into the interior of main parachute 208,particularly when main parachute 208 is configured with a pulled downvent. Turbulence and/or other forces may then force the expended reefingcutter 212 into contact with a portion of main parachute 208,potentially rupturing and/or otherwise damaging or impairing theoperation of main parachute 208. Therefore, in certain exemplaryembodiments, reefing cutter 212 may be configured to fall away frominlet parachute 202 after operation of reefing cutter 212 in order toprevent contact with main parachute 208 and/or other components ofparachute inlet control system 200. In other exemplary embodiments,reefing cutter 212 and/or other components of parachute inlet controlsystem 200 may be configured to retain reefing cutter 212 at a desiredlocation with respect to main parachute 208, such as adjacent the skirtof main parachute 208.

For example, with reference now to FIG. 5, in accordance with anexemplary embodiment, parachute inlet control system 200 is configuredwith lacing loops 204 having a length X. A reefing cutter 212 is coupledto inlet parachute 202 via a lacing loop 204 having a length of aboutone-third (⅓) X. Additionally, one or more lacing loops 204 coupled toreefing cutter 212 are configured with a length of about two-thirds (⅔)X. This combination of lacing loops 204 allows reefing cutter 212 and/orthe end loops of one or more lacing loops 204 to be located generallyproximate the skirt of main parachute 208, rather than generallyproximate the skirt of inlet parachute 202. Moreover, longer and/orshorter lengths for particular lacing loops 204 may be utilized, asdesired, and the examples provided are given by way of instruction andnot by way of limitation. A cordage or webbing loop may thus join lacingloops 204 and/or reefing cutter 212 to the skirt of main parachute 208without deforming main parachute 208 and/or inlet parachute 202. In thismanner, after inlet parachute 202 has deployed, and reefing cutter 212has functioned, inlet parachute 202 unlaces from the skirt of mainparachute 208, and reefing cutter 212 is retained along the skirt ofmain parachute 208. Thus, reefing cutter 212 is prevented from movingfurther into the interior of main parachute 208 and/or damaging othercomponents of parachute inlet control system 200.

As will be appreciated by one of ordinary skill in the art, principlesof the present disclosure may be reflected in a computer program producton a tangible computer-readable storage medium having computer-readableprogram code means embodied in the storage medium. Any suitablecomputer-readable storage medium may be utilized, including magneticstorage devices (hard disks, floppy disks, and the like), opticalstorage devices (CD-ROMs, DVDs, Blu-Ray discs, and the like), flashmemory, and/or the like. These computer program instructions may beloaded onto a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions that execute on the computer or other programmabledata processing apparatus create means for implementing the functionsspecified in the flowchart block or blocks. These computer programinstructions may also be stored in a computer-readable memory that candirect a computer or other programmable data processing apparatus tofunction in a particular manner, such that the instructions stored inthe computer-readable memory produce an article of manufacture includinginstruction means which implement the function specified in theflowchart block or blocks. The computer program instructions may also beloaded onto a computer or other programmable data processing apparatusto cause a series of operational steps to be performed on the computeror other programmable apparatus to produce a computer-implementedprocess such that the instructions which execute on the computer orother programmable apparatus provide steps for implementing thefunctions specified in the flowchart block or blocks.

While the principles of this disclosure have been shown in variousembodiments, many modifications of structure, arrangements, proportions,the elements, materials and components, used in practice, which areparticularly adapted for a specific environment and operatingrequirements may be used without departing from the principles and scopeof this disclosure. These and other changes or modifications areintended to be included within the scope of the present disclosure andmay be expressed in the following claims.

In the foregoing specification, the invention has been described withreference to various embodiments. However, one of ordinary skill in theart appreciates that various modifications and changes can be madewithout departing from the scope of the present invention as set forthin the claims below. Accordingly, the specification is to be regarded inan illustrative rather than a restrictive sense, and all suchmodifications are intended to be included within the scope of thepresent invention. Likewise, benefits, other advantages, and solutionsto problems have been described above with regard to variousembodiments. However, benefits, advantages, solutions to problems, andany element(s) that may cause any benefit, advantage, or solution tooccur or become more pronounced are not to be construed as a critical,required, or essential feature or element of any or all the claims. Asused herein, the terms “comprises,” “comprising,” or any other variationthereof, are intended to cover a non-exclusive inclusion, such that aprocess, method, article, or apparatus that comprises a list of elementsdoes not include only those elements but may include other elements notexpressly listed or inherent to such process, method, article, orapparatus. Also, as used herein, the terms “coupled,” “coupling,” or anyother variation thereof, are intended to cover a physical connection, anelectrical connection, a magnetic connection, an optical connection, acommunicative connection, a functional connection, and/or any otherconnection. When language similar to “at least one of A, B, or C” isused in the claims, the phrase is intended to mean any of the following:(1) at least one of A; (2) at least one of B; (3) at least one of C; (4)at least one of A and at least one of B; (5) at least one of B and atleast one of C; (6) at least one of A and at least one of C; or (7) atleast one of A, at least one of B, and at least one of C.

1. A parachute inlet control system, comprising: an inlet parachute; and a plurality of lacing loops configured to couple the inlet parachute to a main parachute; wherein each of the plurality of lacing loops is configured with an end loop, and wherein, when the inlet parachute is coupled to the main parachute, at least one of the plurality of lacing loops is threaded through the end loop of another of the plurality of lacing loops.
 2. The system of claim 1, wherein the inlet parachute is configured to inflate in the inlet area of the main parachute.
 3. The system of claim 1, wherein, when the inlet parachute is coupled to the main parachute, the plurality of lacing loops are threaded through reefing rings on the main parachute.
 4. The system of claim 1, wherein the length of each of the plurality of lacing loops is between 10 percent of the diameter of the inlet parachute and 50 percent of the diameter of the inlet parachute.
 5. The system of claim 1, wherein the inlet parachute is configured to cause airflow between the inlet parachute and the main parachute to force a skirt of the main parachute into an opened shape.
 6. The system of claim 1, further comprising a plurality of inlet vent lines configured to couple to a center line of the main parachute.
 7. The system of claim 1, further comprising a reefing cutter, wherein the reefing cutter is configured to sever at least one of the lacing loops responsive to at least one of: an activation command received by the reefing cutter, a predetermined time period, altitude of a payload, or velocity of a payload.
 8. A method for inflating a parachute, the method comprising: providing an inlet parachute; and coupling the inlet parachute to a main parachute via a plurality of lacing loops, wherein each lacing loop is configured with an end loop, wherein at least one of the plurality of lacing loops is threaded through the end loop of another of the plurality of lacing loops, and wherein the inlet parachute is configured to inflate within the inlet area of the main parachute.
 9. The method of claim 8, wherein coupling the inlet parachute to the main parachute comprises: threading a first lacing loop of the inlet parachute through a first reefing ring located on a skirt of the main parachute; threading a second lacing loop of the inlet parachute through the end loop of the first lacing loop; and threading the second lacing loop through a second reefing ring located on the skirt of the main parachute.
 10. The method of claim 8, further comprising inflating the inlet parachute to cause airflow between a skirt of the inlet parachute and a skirt of the main parachute to force the skirt of the main parachute into an opened shape.
 11. The method of claim 10, wherein the size of the opened shape is determined by the length of the plurality of lacing loops.
 12. The method of claim 10, wherein threading the first lacing loop through the first reefing ring prevents the main parachute from fully opening when the main parachute is deployed.
 13. The method of claim 9, wherein the first lacing loop is threaded through multiple reefing rings on the skirt of the main parachute.
 14. The method of claim 8, wherein the main parachute is configured without reefing rings, and wherein coupling the inlet parachute to the main parachute comprises encircling a lacing loop of the inlet parachute around a suspension line of the main parachute.
 15. The method of claim 14, wherein one lacing loop is encircled around multiple suspension lines of the main parachute.
 16. The method of claim 14, wherein encircling a lacing loop of the inlet parachute around a suspension line of the main parachute prevents the main parachute from fully opening when the main parachute is deployed.
 17. The method of claim 10, further comprising releasing at least one of the plurality of lacing loops to cause the inlet parachute to cease functioning as a reefing component for the main parachute.
 18. The method of claim 10, further comprising severing a cut loop to cause the inlet parachute to separate from the skirt of the main parachute, wherein the cut loop passes through the end loop of at least one of the plurality of lacing loops.
 19. The method of claim 10, wherein the main parachute is part of a parachute cluster comprising multiple main parachutes, and wherein each main parachute in the parachute cluster is coupled to a corresponding inlet parachute.
 20. The method of claim 10, wherein inflation of the inlet parachute causes the main parachute to ingest air more rapidly than if the main parachute was not coupled to an inlet parachute. 